Ph Indicator Dye
Ph Indicator Dye - Related Videos
08:14
Assessing T-cell Receptor-Induced Calcium Influx Using a Calcium Indicator Dye
0 Views •
2025
This video analyzes T-cell receptor-induced calcium influx in T-cells. Anti-CD3 antibodies activate the T-cell signaling pathways, leading to an increase in intracellular calcium ions that bind with Indo-1 dye. In flow cytometry, a spectrum shift from the calcium-free state to the calcium-bound state correlates with T-cell receptor-induced calcium influx.
02:39
Indicators
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2020
Certain organic substances change color in dilute solution when the hydronium ion concentration reaches a particular value. For example, phenolphthalein is a colorless substance in any aqueous solution with a hydronium ion concentration greater than 5.0 × 10−9 M (pH < 8.3). In more basic solutions where the hydronium ion concentration is less than 5.0 × 10−9 M (pH > 8.3), it is red or pink. Substances such as phenolphthalein, which can be used to determine the pH of a solution, are called...
15:16
Loading Drosophila Nerve Terminals with Calcium Indicators
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Cited by 17 •
2007
Calcium is a ubiquitous messenger in the nervous system, essential for triggering neurotransmitter release and changes in synaptic strength. Here we demonstrate a technique for loading Ca2+-indicators into Drosophila nerve terminals. We also demonstrate fabrication of the required apparatus and emphasize points critical for the technique's success.
02:39
Imaging the Mitochondrial Redox State in Primary Neurons Using a Ratiometric Indicator
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2025
Source: Katsalifis, A., et al. Live Imaging of the Mitochondrial Glutathione Redox State in Primary Neurons using a Ratiometric Indicator. J. Vis. Exp. (2021)This video demonstrates the imaging of mitochondrial redox state in primary neurons using a ratiometric fluorescent indicator. By applying two excitation wavelengths under a fluorescence microscope, the fluorescence intensity ratio is measured to assess mitochondrial oxidation. The protocol includes N-methyl-D-aspartate (NMDA) stimulation...
08:17
Water Quality Analysis via Indicator Organisms
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2023
Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba -The University of Arizona Demonstrating Author: Luisa Ikner Water quality analysis monitors anthropogenic influences such as pollutants, nutrients, pathogens, and any other constituent that can impact the water’s integrity as a resource. Fecal contamination contributes microbial pathogens that threaten plant, animal, and human health with disease or illness. Increasing water demands and strict quality standards require that water...
FAQs
The key event is a change in protonation state. As acidity or alkalinity shifts, the dye gains or loses protons, changing its molecular structure. That structural change alters which wavelengths of light the compound absorbs, so the solution appears a different color. The transition is therefore a chemical response to changing hydrogen-ion conditions, not merely a visual effect.
A dye is most informative when the solution’s expected pH falls within its characteristic transition range, often near its pKa, the value associated with the dye’s acid-base transition. Within that interval, modest changes in acidity or alkalinity can produce an observable color shift. Matching the dye to the relevant range makes biological monitoring more interpretable.
Protonation state links the dye’s visible signal to conditions that biological systems depend on. Changes in acidity can affect buffer conditions, enzyme activity, molecular stability, and cell viability. By indicating that acid-base conditions have shifted, the dye helps researchers recognize whether an experimental environment remains compatible with the intended biological process.
The dye can be used as a visual check while preparing or maintaining buffers and cell culture media. Researchers observe whether the color corresponds to the expected region of the dye’s transition range, then use that information to detect acid-base changes. This supports routine control of environments where enzyme function, molecular stability, or cell viability must be preserved.
During titration, progressive addition of one solution changes the acidity or alkalinity of another. An indicator dye makes those changes visible through its characteristic color transition, helping researchers identify and interpret the point at which the solution enters the dye’s transition range. This provides a practical visual readout for acid-base behavior in the experiment.
A color shift shows that the solution’s acid-base conditions have changed and can provide a visible estimate of its pH. It does not by itself identify the cause of the change or establish a precise pH value beyond the dye’s characteristic transition range. Researchers should therefore interpret the signal in relation to the selected dye and experimental context.